The present invention relates to antimicrobial compositions containing a borinic acid derivative, e.g. a borinic ester. In particular embodiments, the invention covers oral compositions, for example dentifrice, for reducing bacteria in the mouth, e.g. for inhibiting and reducing plaque, gingivitis and dental caries.
Although some borinic esters are effective as antibacterial agents, incorporating borinic esters into oral care compositions presents difficulties, as borinic esters have proven to be unstable when added to aqueous compositions. For example, borinic esters may hydrolyze and decompose, e.g., in oral care compositions. Additionally, borinic esters may be insoluble in aqueous compositions. For example, the solubility of 3-hydroxypyridine-2-carbonyloxy-bis(3-chloro-4-methylphenyl)-borane in water is only 100 ppm, and its solubility in various oils may be less than 0.5%. There remains a need to develop compositions and methods to incorporate borinic acid derivatives stably in oral care compositions.